; Constants
WR_CMD      EQU 0FF2CH
WR_DATA     EQU 0FF2DH
READ_STAT   EQU 0FF2EH
READ_DATA   EQU 0FF2FH

INIT_DISP   EQU 038H
CLEAR       EQU 001H
LCD_ON      EQU 00FH

SEC:        DS 1
MIN:        DS 1
HOUR:       DS 1
COUNT:      DS 1
;---------------------------
    ORG 0
    call lcd_init
    SJMP $

;---------------------------
; LCD commands


;-------------------------------------------
; Uses Acumulator
;-------------------------------------------
lcd_init:
    mov A, #INIT_DISP
    call lcd_wr_cmd
    mov A, #CLEAR
    call lcd_wr_cmd
    mov A, #LCD_ON
    call lcd_wr_cmd
    RET

;-------------------------------------------
; A - command to send
;-------------------------------------------
lcd_wr_cmd:
    push ACC
    mov DPTR, #READ_STAT

    LOOP_WR_CMD:
        movx A, @DPTR
        jb ACC.7, LOOP_WR_CMD
        mov DPTR, #WR_CMD
        pop ACC
        movx @DPTR, A
    RET

;-------------------------------------------
; A - data to send
;-------------------------------------------
lcd_wr_data:
    push ACC
    mov DPTR, #READ_STAT

    LOOP_WR_DATA:
        movx A, @DPTR
        jb ACC.7, LOOP_WR_DATA
        mov DPTR, #WR_DATA
        pop ACC
        movx @DPTR, A
    RET

;-------------------------------------------
; A - char to write on display
;-------------------------------------------
lcd_putc:
    call lcd_wr_data
    RET

;-------------------------------------------
; A - decimal to write on display, uses A and B registers
;-------------------------------------------
lcd_put_dec:
    mov B, #10
    div AB
    add A, #'0'
    call lcd_wr_data

    mov A, B
    add A, #'0'
    call lcd_wr_data
    RET

;-------------------------------------------
; A - position format A = (---yxxxx)
; Uses A, B, R6, R7
;-------------------------------------------
lcd_goto_xy:
    anl A, #00011111b
    jnb ACC.4, SET_X

    SET_Y:
        anl A, #00001111b
        add A, #40H

    SET_X:
         orl A, #010000000b

    call lcd_wr_cmd
    RET
END